Had a friend who spent the first 6 years of his Navy career at a base in Tennessee, finally got sea duty at Norfolk. He went into town on a Saturday night walked into a bar and ordered a beer.
My buddy had a "baby" face (he was 24 by then) so the bartender checked his ID card and reluctantly gave him his beer.
Buzz said the bar had a "big fish" mounted above the booze and he asked the bartender what kind of fish that was- the bartender snatched his beef off the bar and said "Any sailor who'd been in the Navy for 6 years would know what a hammerhead shark was!"
Buzz was immediately "86'd"!